Photographic process

ABSTRACT

THIS DISCLOSURE IS DIRECTED TO A METHOD OF PHOTOGRAPHY INVOLVING THE USE OF BLUE LIGHT TO SENSITIZE A FILM THEREBY ENABLING IT TO BE IMAGED BY LIGHT OF THE VISIBLE RED AND INFRARED WAVELENGTHS, E.G., IN THE WAVE LENGTH RANGE OF 630 TO 4200 MILLIMICRONS. THIS IMAGE CAN BE FIXED BY WASHING WITH A NON-POLAR SOLVENT.

June 1 1971 c, BERTELSQN ETAL 3,582,332

PHOTOGRAPHIC PROCES 5 Filed Feb. 1, 1966 2 Sheets-Sheet 1 FIG. I

highly non-polar polymeric material film-layer having molecularly dispersed in it compounds I, II, III

activated by blue) imaged by red photo-sensitive layer (optional) I RCX where X is taken from the group consisting of Cl, Br,

and I, where C is carbon, and where R is taken from the group consisting of X, halogen-substituted alkyl, 'acyl and aroyl;

II a dialkylamino substituted dyestuff; and

III the compound Where R is alkyl 11 is 0,l,2,3 R is H, or atoms to complete a benzene-ring Styryl linkage is in position 2 or 4 FIG. IA

highly non-polar polymeric material layer having in molecular dispersion compound I (see Fig. 1)

photo-sensitive layer pair highly non-polar polymeric material layer having in molecular dispersion compound II and III (see Fig. 1)

oubstrate (optional) INVENTORS ROBERT C. BERTELSON 5 KENNETH D. GLANZ BY r I C, THEIR ATTORNEYS June 1, 1971 R. c. BERTELSON ET AL PHOTOGRAPHIC PROCESS Filed Feb. 1, Q 1966 2 Sheets-Sheet 2 PROCESS FOR USING LAYER OF FIGS. 1 AND 1A Image Formation To Activate It Direct Blue Light Over Area To Be Subjected To Activat ion Imaging Optional Washing Layer With By Extraction Non-polar Solvent Liquid To Desensitize Background Fixing INVENTORS ROBERT C. BERTELSON 8 KENNETH D. GLANZ (Awe THEIR ATTORNEYS United States Patent 3,582,332 PHOTOGRAPHIC PROCESS Robert C. Bertelson and Kenneth D. Glanz, Kettering,

Ohio, assignors to The National Cash Register Company, Dayton, Ohio Filed Feb. 1, 1966, Ser. No. 524,165 Int. Cl. G03c 5/24 US. CI. 96-48 4 Claims ABSTRACT OF THE DISCLOSURE This disclosure is directed to a method of photography involving the use of blue light to sensitize a film thereby enabling it to be imaged by light of the visible red and infrared wavelengths, e.g., in the wave length range of 630 to 4200 millimicrons. This image can be fixed by Washing with a non-polar solvent.

This invention relates to a photographic element and its uses, and particularly pertains to such an element useful in that, while it .is normally insensitive to red light, a brief exposure to blue light, reckoned in terms of a second, gives the element red-light-sensitivity of such degree that an image may be made on the blue-light-preexposed area by red light alone; but this red-responsiveness is accompanied by an increased sensitivity to all bands of the visible spectrum including blue and longer wave-lengths than blue, so that an image also may be made on the blue-sensitized element with any of the visible light wavelengths between ultraviolet and red. This invention, however, enables a photograph to be made by red light alone, and is of value especially under conditions where no blue, green, or yellow light is coming from the photographed object or where the blue, green, or yellow light is filtered out more or less in the transmission medium between the object being photographed and the novel photographic element. The image on the photographic element, in its preferred form, appears as a reddish-blue area against a yellow background area, yellow being the color of the photographic element before it is subjected to red light. Without the presence of a blue-color-contributing chromogenic dyestufl component of the preferred form of the invention, the image is red.

The reddish-blue or red image is due to reaction products that are insoluble with respect to certain highly nonpolar organic solvent liquids applied thereto, and the residual unreacted sensitizing materials, being soluble in the same solvent liquids, may be removed from the nonimage areas by washing the element with such solvents, thereby to fix the non-image areas of the photographic element against modification by light if removal of the sensitizing material is so carried out.

The photographic element may in part be a self-supporting layer of polymeric material having in the selfsupporting layer only part of the necessary reactant compounds, or the layer may be supported on a substrate material which may be flexible or rigid, opaque or transparent, and colored or not, as desired to enable it to cooperate with the photographic layer element in its ultimate use. If the element is a single layer, it must be used while wet or moist; and if the element is a two-layer system, at least one of the layers-the last provided must be wet or moist. While the general class of the used sensitizing compounds is known for making other kinds of light-sensitive layers, selected ones of known compounds are provided in novel combinations and amounts and are used in a manner especially suitable for the purposes of this invention. Attention is directed to United States Letters Patent Nos. 3,095,303; 3,102,810; and 3,-

3,582,332 Patented June 1, 1971 121,633, issued to Robert H. Sprague et al. on June 25, 1963; Sept. 3, 1963; and Feb. 18, 1964, respectively, which show some of the compounds eligible for use as reactant components.

The invention is deemed novel with respect to the property of the elements being useful by the consecutive application thereto of an activating flood of blue light to an area to thereby sensitive (activate) said area uniformly, and then the application to said activated area of an image-forming red light pattern representing the image to be recorded, using conventional camera equipment, at speeds reckoned in seconds short of a minute, or perhaps somewhat longer. Tracer beam light or stencil masks are obvious alternative red light control means.

In the drawings, the legend (optional) refers to materials. The substrate in FIG. 1A may be dispensed with, if the basic film is self-supporting.

The invention finds utility in that the fixing of the image is by a single step of solvent-extraction of unreacted sensitizing matter, as by washing of the photographic layer element with a solvent or with a mixture of solvents to rid the background area of at least an essential moiety of such unreacted material.

The images so formed by light may be of molecular resolution limit rather than the coarser resolution limit of images associated with the crystalline state of imageforming material. In time, the reddish-blue or red image in the element of this invention will evidence some microaggregation of colored molecular entitiesbut not as gross as the silver salt crystal size encountered in silver halide systems.

The invenion will be specified in conjunction with a drawing in which:

FIG. 1 is a diagrammatic representation of a substratesupported photographic element layer pervaded with the preferred materials, such materials being sensitive when the layer is wet, and the materials being identified by the numerals I, II, and III;

FIG. 1A represents a double-layer sandwich construction instead of a single-layer construction of the photographic element of FIG. 1, wherein there is not complete interspersion of materials I, II, and III except by contact migration, only the top layer being of necessity Wet to give sensitivity, and the preferred disposition of the layers being indicated, although they may be reversed as to which is the dry bottom layer; and

FIG. 2 represents a flow-chart of the method of the use of the novel layer.

It is to be understood that the invention uniquely contemplates the use of red light, instead of light of shorter wave-lengths, to make an image in the layer after it is activated by brief flooding treatment with blue light. The sensitivity for making an image by further controlled application of blue light is still retained, however, if it is desired to use the element in that manner. As this bluelight sensitivity has been known in some respects, as set out in the patents cited above, the advance in the art as encompassed by this invention is in the provision of a process of using a photograph element with area-controlled red light to produce an image, and in the provision of a process for using such controlled red-light after a brief pre-sensitization of the element in the use areas by flooding with blue light.

The sensitization life of the layer is dependent on the wetness of the layer, it being no longer sensitive when dry. Hence, the evaporation conditions afforded by the ambient atmosphere are of importance, and the wetness might be prolonged indefinitely if a freshly-made layer were housed in a hermetically-sealed camera.

The objectives of the invention having been disclosed, the sensitizing materials will be specified next.

The photo-reactant material content layer comprises the film-forming material and its dispersed molecular content of three components, I, II, and III. Cmponent I is a compound of the general formula RCX where X is taken from the group consisting of chlorine, bromine, and iodine, and where R is taken from the group consisting of X, halogen substituted alkyl, acyl, and aroyl. Component II is a leuco dyestutf containing at least one dimethylamino group as exemplified by leuco crystal violet; leuco malachite green; 2-p-nitrobenzoamido leuco crystal violet; di-

carboxy leuco crystal violet; Z-nitro-leuco crystal violet; malachite green leuco cyanide; and crystal violet lactone, all of which yield a blue color. Hence it will be understood that dimethylamino derivatives of leucotriphenylmethane dyes can be employed as Component II. Component II is not necessary if only a red image is desired. If more of the green and blue portions of the spectrum are desired in the final image, a Class II compound should be employed. Class III compounds are of the structure where R is alkyl, n is zero, 1, 2, or 3, and R and R is H or atoms to complete a benzene ring portion of a quinoline group.

Appropriate films may be prepared with solutions of cellulose acetate butyrate or polystyrene, as will be specified in the examples as materials that withstand the solvent-extraction step of fixing the image. Accordingly the highly non-polar polymeric material can be selected from the group consisting of cellulose acetate butyrate and polystyrene.

EXAMPLE I A film-forming solution batch is formed according to the following ratio pattern: One gram of cellulose acetate butyrate of a quality to yield a viscosity determination of one half-second when tested according to ASTM-D 817- 64 (a y32-l HCI1 stainless steel ball requires one half-second to fall a distance of two inches in a 20% solution of the polymeric materialthe solvent being substantially acetone) was dissolved in a solvent system composed of eight milliliters of toluene, one milliliter of ethanol, and one milliliter of butanol.

Twenty-five milligrams of 4-(p-dimethylaminostyryl) quinoline and 1.4 grams of carbon tetrabromide were dissolved in eight milliliters of the above polymeric solution. The dye-polymeric-material solution system was cast as a wet film six mils (0.006 inch) thick onto a five-mil-thiek polyethylene terephthalate sheet (sold as Mylar by E. I. du Pont de Nemours & Company) using a drawdo wn bar and a vacuum- 'plate-equipped substrate support to yield the photographic element of FIG. 1 without the chromogenic material II .This cast film, while wet, was exposed within two minutes of application to a sensitizing light having a color temperature of 5500 degrees K. in a manner alfording a surface illumination of 2050 meter-candles. The source was a 500-watt Quartz-Line lamp, color-corrected with a Corning glass filter number 5900, three millimeters thick.

The blue-light-sensitized film was exposed three minutes to imaging light in the wave-length range of 630 to 4200 millimicrons for maximum contrast image formation to form a red image, and the finally-exposed film was fixed by a solvent rinse, the solvent being composed of 72.2% petroleum distillate (initial boiling point 140 degrees Fahrenheit to 150 degrees Fahenheit), 18.2% toluene, and 9.1% acetone, by volume.

I 4 EXAMPLE II Six milligrams of 4-(p-dimethylaminostyryl) quinoline, twenty-five milligrams of leuco crystal violet, and 1.4 grams of carbon tetrabromide were dissolved in eight milliliters of a 10%, by weight, solution of polystyrene (about 200,000 molecular weight) in benzene. This system was cast into a film on a substrate and sensitized as in Example 1. Two minutes of image exposure thereafter to light having a wave-length-range of 680 to 3200 millimicrons and affording a surface intensity equivalent to Example I was sufficient to yield maximum image contrast of reddish-blue against the background color. The finally exposed film was fixed by a solvent rinse, as in Example I, except that the solvent was petroleum ether and acetone used in a ratio of four to one.

EXAMPLE III All processes, techniques, and materials are the same as in Example II with the exception that leuco malachite green has been substituted for leuco crystal violet.

EXAMPLE IV Twenty-five milligrams of 4-(p-dimethylaminostyryl) quinoline was dissolved in eight milliliters of the polymeric material solution of Example I. This dye solution was cast into a film according to Example I and was allowed to dry by solvent evaporation for five to ten minutes.

Separately, 1.4 grams of carbon tetrabrornide was dissolved in eight milliliters of the polymeric solution of Example 'I, and this solution was cast over the dye film prepared previously to give the structure of FIG. 1A. Sensitization, image-forming exposure, and fixing were carried out as in Example I.

The single-layer product of Examples I, II, and III is shown in FIG. 1 of the drawing, and the double-layer product of Example IV is shown in FIG. 1A of the drawing. In the double-layer system, only the second layer need be in wet condition for image-taking, and the first layer may be dried to a self-supporting film before application of the carbon-tetrabromide-containing layer.

Carbon tetrabromide is by far the best of RCX; compounds and for all practical purposes is the one to be used.

As between the Components I, II, and 111, it has been found that as little as from 1.4/1 to 200/1 as between Component I and Components II and III combined gives a good result, but the preferred range is from 10/1 to 1. As between Components I and III, they may be used in a 1/ l to a 5/1 ratio range.

The exposure times are maxima, with less pronounced effects resulting from less exposure. i v

The preferred 4-(p-dimethylaminostyryl) quinoline in the examples, which is the Component III of FIG. 1 of the drawing, can be prepared according to the disclosure of the publication appearing in Journal of the American Chemical Society, volume 68, 1332 (1946). The generalized structural formula of FIG. 1 of the drawings and of the United States Letters Patent No. 3,095,303, to which reference has been made, may be used to select equivalent styryl dye compositions for Component III.

What is claimed is:

1. A method of photography'wherein the image is made by red light application to a sensitized layer in a photographic camera, including the steps of (a) providing a highly-non-polar polymeric material film selected from the group consisting of cellulose acetate butyrate and polystyrene wet with a solvent therefor, said film having molecularly dispersed in it (I) a compound of the general formula =RCX where X is taken from the group consisting of Cl, Br, and I, where C is carbon, and where R is taken from the group consisting of X, halogen substituted alkyl, acyl, and aroyl;

(II) a dimethylamino derivative of a leucotriphenyl-methane dyestuff; and (III) a styryl dyestuff of the structural formual where R is alkyl, n is 0, 1, 2, 3, R R is H, or atoms to complete a benzene ring portion of a quinoline group, and the styryl linkage is in position 2 or 4;

(-b) briefly flooding the prospective use area of the layer in paragraph (a) with blue light while said film is wet with said solvent to sensitize it uniformly in said use area; and

(c) then forming an image in the area while said film is wet with said solvent by selective application of red light in the wave-length range of 630 to 4200 millimicrons.

2. A method of photography including the steps of (a) providing a layer of polymeric material selected from the group consisting of cellulose acetate butyrate and polystyrene wet with a solvent therefor and containing, in molecular dispersion,

(I) a compound of the formula RCX' where X is taken from the group consisting of Cl, Br, and I, where C is carbon, and where R is taken from the group consisting of X, halogen-substituted alkyl, acyl, and aroyl;

(II) a dimethylamino derivative of a leucotriphenylmethane dyestuff; and

(III) a styryl dyestufi of the structural formula where R is alkyl, n is 0, 1, 2, 3, R and R is H or atoms to complete a benzene ring portion of a quinoline group;

(b) sensitizing a selected wet area of the layer in paragraph (a) for use by flooding it with blue light to uniformly sensitize said area;

(c) then directing red light in the wavelength range of 630 to 4200 millimicrons to selected places in the wet area to form an image; and

(d) washing the layer with a non-polar solvent to extract non-reacted image-forming material.

3. A method of photography wherein the image is made by red light application to a sensitized layer in a photographic camera, including the steps of (a) providing a highly non-polar polymeric material film selected from the group consisting of cellulose acetate butyrate and polystyrene wet with a solvent therefor, said film including molecularly dispersed in it a compound of the general formula RCX where X is taken from the group consisting of Cl, Br,

and I, where C is carbon, and where R is taken from the group consisting of X, halogen-substituted alkyl, acyl, and aroyl; and

a styryl dyestuif of the structural formula where R is alkyl, n is 0, 1, 2, 3, R R is H, or atoms to complete a benzene ring portion of a quinoline group, and the styryl linkage is in position 2 or 4;

(b) briefly flooding the prospective use area of the layer in paragraph (a) while wet with said solvent with blue light to sensitize it uniformly in said use area; and

(c) then forming an image in the area while said film is wet with said solvent by selective application of red light in the wavelength range of 630 to 4200 millimicrons.

4. A method of photography including the steps of (a) providing a layer of polymeric material selected from the group consisting of cellulose acetate butyrate and polystyrene wet with a solvent therefor and including, in molecular dispersion,

a compound of the formula RCX where X is taken from the group consisting of Cl, Br, and I, where C is carbon, and where -R is taken from the group consisting of X, halogen-substituted alkyl, acyl, and aroyl; and

a styryl dyestutf of the structural formula CH=CH r- NR 31 a 2 where R is alkyl, n is 0, l, 2, 3, R and R is H or atoms to complete a benzene ring portion of a quinoline group;

(b) sensitizing a selected wet area of the layer in paragraph (a) for use by flooding it with blue light to sensitize it uniformly in said area;

(0) then directing red light in the wavelength range of 630 to 4200 millimicrons to selected places in the sensitized wet area to from an image; and

(d) washing the layer with a non-polar solvent to extract non-reacted image-forming material.

References Cited UNITED STATES PATENTS 3,042,517 7/ 1962 Wainer 96-48 DAVID KLEIN, Primary Examiner US. Cl. XJR. 96--90 

